Design Of A Power Transmission Line Inspection Robot And Autonomous Line Grasping Control

With the rapid evolution of robots and robotics,the power transmission line inspection robot is developed as a new way for the power transmission line inspection work.This new-type robot has sevel features,walking on the power transmission line,overcoming the obstacles on the line,and inspecting the power conditioning and transmission equipments with on-board sensors,thus decreasing the operational difficulty of the inspection work effectively and improving the economic efficiency dramatically.The robot should walk on the line without any risk of falling and overcome obstacles on the line.Since the power transmission line is installed hanging with ten several meters from the ground,it is difficult to get the 3-D position of the line and then control the robot to grasp the line after overcoming the on-line obstacle automatically or remotely.Therefore,walking on the line and grasping the line after overcoming an obstacle,as the most basic features of the power transmission line inspection robot,are the most difficult technical challenges.Concerning with the line-walking and line-grasping technologies for the power transmission line insepction robot,this study gives detailed analysis and evaluation of the power transmission line inspection scenarios,requiments and existing technologies,and gives a new designed inspection robot.Meanwhile,a new adaptive monocular visual servong algorithm,using the image lines features to control the robot,is proposed to solve the line-grasping problem after overcoming an obstacle.The main points of this research are as below:A new design of power transmission line inspection robot.The existing power transmission line inspection robots are too complex,heavy and not able to run in several complex environments.In order to solve the problems of these exsiting inspection robots,a dual-arm platform is designed and it can walking on the line with the drive of v-groove wheels mounted on the arms top.A new mechanism design with removable counterweight is proposed.By controlling the position of counterweight and rotating the robot joints joints synchronously and in real time,the new robot lifts its arm up from the line to overcome the obstacle.The two arms of the robot overcome the on-line obstacles alternately.A new approach to grasping the transmission line autonomously for the off-line arm of the power transmission line inspectin robot.The existing power transmission line inspection robots are not able to overcome on-line obstacles autonomously due to lacking the ability for autonomous transmission line grasping.In order to solve the problem,a new adaptive monocular visual servoing algorithm is proposed.Camers are mounted on the arms top respectively,in eye-in-hand setup,to capture the power transmission line features.A depth-independent image Jacobian matrix is derived to map the image errors to the robot joints inputs.A new adaptive algorithm is proposed to estimate the unknown camera intrinsic and extrinsic parameters and the 3-D position position of the power transmission line.By capturing several images in the movement process of the robot,the errors between the line features extracted from these images and calculated with the estimated parameters are used to update the parameters estimation in real time.The controller use the images errors,estimated parameters and the joints positions to calculate the joints velocities inputs.The asymptotic convergence is analyzed by using the Lyapunov method.In addition,the image features are one-to-one mapping to the robot gesture due to the limited joint freedom degree.After setting the image features corresponding to the robot gesture in grasping the line setup,the arm can grasp the line automatically by using the new monocular visual servoing algorithm.Simulations and experiments.The new robot model is built based on Matlab and Robotics toolkits,and the performance of the adaptive monocular visual servoing algorithm by using line features is demonstrate by simulations.An experimental prototype is made and put in a simulated power transmission line inspection scenario.Experiments results show that the proposed robot design and visual servoing algorithm are effective,and the robot can walk on the line and grasp the line automatically.In summary,the new designed robot can walk on the line,overcome the obstacle on the line,and inspect the power conditioning and transmission equipments with on-board sensors.The the adaptive monocular visual servoing algorithm makes it possible for the robot to grasp the line automatically after overcoming an obstacle.In consequence,this study has proposed a new way for the power transmission line inspection work,thus ensuring the human safety of the inspection workers and improving the quality and efficiency of the inspection dramatically,which will make a big difference.